Core C: Genotyping Core Laboratory. A systematic evaluation of common variation within each candidate gene will be performed by haplotype- and genotype-based analyses. This genomic approach, and the associated analytic and statistical methodologies, have been developed by the Directors of the Genotyping Core laboratory and Project Directors of this Program Project. The Genotyping Core laboratory will be responsible for the processing and storage of blood samples and buccal swabs collected as part of the individual Projects of this Program. In addition, the role of the Core laboratory will be to provide DNA extraction, template preparation and high-throughput SNP genotyping. For each Project, blood or buccal samples will be assigned study specific IDs and stored at -80[unreadable]C and 4[unreadable]C, respectively. DNA isolation will be performed by robotics using Qiagen 96- well DNA kits and DNA storage will be designed for both 96 and 384-well genotyping platforms. The Core laboratory is equipped with the Tomtec Quadra 384 and Multimec 96 robotic systems for rapid and efficient DNA transfer and sub-aliquoting. SNP genotyping will be conducted using both the Illumina Genotyping System and the Taqman allelic discrimination assay using the ABI 7700 sequence detection system. Microsatellite polymorphisms will be analyzed on an ABI 3700 DNA Analyzer. The Core has developed a computerized genotype tracking system for data storage and stringent quality control procedures will be implemented to validate assay reproducibility and ensure genotype quality. The Co-Directors of the Genotyping Core laboratory will actively participate in the selection of haplotype-tagging SNPs (htSNPs) and will work closely with the other Project and Core Leaders in the analysis and interpretation of haplotype-based data.